Forficulidx and Chelisochidx, families of Dermatoptera. 105 
and the Ancistrogastring ; in the elongate forceps, slightly 
dilated body and scarcely keeled elytra it recalls the 
former, but in the incipient lateral folds of the abdomen 
and the form of the last dorsal segment, and also the 
form of the apex of the male forceps, it approaches the 
latter. 
Genus 7.—CosMIELLA, Verhoeff. 
Antenne 10-segmentatx, segmentis 3, 4 et 5 subsquantibus, 
longis, cylindricis ; pronotum caput latitudine subequans, haud 
longius quam latius, subquadratum ; elytra lata, carinula humerali 
sat distincta, per dimidium elytri percurrenti ; alee nulla ; abdomen 
convexum, medio dilatatum ; plicis lateralibus distinctis ; segmentis 
lateribus inermibus; segmentum ultimum dorsale ¢ angustatum, 
tuberculis duobus vix elevatis instructum ; forecipis bracchia ¢ basi 
contigua, valde elongata, a basi divergentia, tum arcuatim incurva, 
margine superiori dente armata; ? simplicia. 
This genus was erected by Verhoeff for the wingless 
species of Opisthocosmia which have a keel more or less 
pronounced on the elytra; Kirby fixed 0. rebus, Burr, as 
the type of the genus; 0. dubia was included by Verhoeff 
upon the strength of de Bormans’ description, but on 
account of its narrow pronotum, it must be removed ; in 
the shape of the pronotum and elytra this genus ap- 
proaches Ancistrogaster, but in the form of the body and 
forceps it resembles Opisthocosmia ; it is a passage between 
these two chief genera. 
It contains the single species O. rebus, Burr, fixed by 
Kirby as the type. C. aptera, Verhoeff, is removed to 
Skendyle, q.v. 
Sub-family 6.—ANCISTROGASTRIN 4. 
The essential character which distinguishes this sub- 
family from the preceding is the form of the anal segment, 
which is transverse, much broader than long. 
The sides of the abdomen are often recurved in the 
form of depressed sickle-shaped hooks, and the forceps of 
the male are frequently bowed into a characteristic lozenge- 
shaped area. In most genera. the elytra are strongly 
keeled. 
The genera are all American. 
